Cooling air, which is removed from the compressor under high pressure, is needed to cool the components that are in contact with hot gas in a gas turbine, which comprises a compressor, a combustion means and a turbine.
In a gas turbine developed by the applicant, compressed air is removed from a radial stage of a compressor, which is an end stage in this case, through the housing wall in the diffuser part, which wall is arranged on the side of the annular space.
This cooling air is removed from the radial compressor stage, which comprises a rotor disk and a diffuser, which may be either bladed or unbladed. In the case of a bladed diffuser, the cooling air removed is transported within the diffuser vanes through horizontal holes in the direction of the outside of the diffuser. A deadwater space, which reduces the efficiency of the entire compressor stage, frequently develops in such a diffuser near the housing wall.